Mercurial > hg > graal-jvmci-8
view src/share/vm/memory/memRegion.hpp @ 3293:1f4413413144
7039089: G1: changeset for 7037276 broke heap verification, and related cleanups
Summary: In G1 heap verification, we no longer scan perm to G1-collected heap refs as part of process_strong_roots() but rather in a separate explicit oop iteration over the perm gen. This preserves the original perm card-marks. Added a new assertion in younger_refs_iterate() to catch a simple subcase where the user may have forgotten a prior save_marks() call, as happened in the case of G1's attempt to iterate perm to G1 refs when verifying the heap before exit. The assert was deliberately weakened for ParNew+CMS and will be fixed for that combination in a future CR. Also made some (non-G1) cleanups related to code and comments obsoleted by the migration of Symbols to the native heap.
Reviewed-by: iveresov, jmasa, tonyp
author | ysr |
---|---|
date | Tue, 26 Apr 2011 21:17:24 -0700 |
parents | f95d63e2154a |
children | d2a62e0f25eb |
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/* * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #ifndef SHARE_VM_MEMORY_MEMREGION_HPP #define SHARE_VM_MEMORY_MEMREGION_HPP #include "memory/allocation.hpp" #include "utilities/debug.hpp" #include "utilities/globalDefinitions.hpp" // A very simple data structure representing a contigous region // region of address space. // Note that MemRegions are passed by value, not by reference. // The intent is that they remain very small and contain no // objects. class MemRegion VALUE_OBJ_CLASS_SPEC { friend class VMStructs; private: HeapWord* _start; size_t _word_size; public: MemRegion() : _start(NULL), _word_size(0) {}; MemRegion(HeapWord* start, size_t word_size) : _start(start), _word_size(word_size) {}; MemRegion(HeapWord* start, HeapWord* end) : _start(start), _word_size(pointer_delta(end, start)) { assert(end >= start, "incorrect constructor arguments"); } MemRegion(const MemRegion& mr): _start(mr._start), _word_size(mr._word_size) {} MemRegion intersection(const MemRegion mr2) const; // regions must overlap or be adjacent MemRegion _union(const MemRegion mr2) const; // minus will fail a guarantee if mr2 is interior to this, // since there's no way to return 2 disjoint regions. MemRegion minus(const MemRegion mr2) const; HeapWord* start() const { return _start; } HeapWord* end() const { return _start + _word_size; } HeapWord* last() const { return _start + _word_size - 1; } void set_start(HeapWord* start) { _start = start; } void set_end(HeapWord* end) { _word_size = pointer_delta(end, _start); } void set_word_size(size_t word_size) { _word_size = word_size; } bool contains(const MemRegion mr2) const { return _start <= mr2._start && end() >= mr2.end(); } bool contains(const void* addr) const { return addr >= (void*)_start && addr < (void*)end(); } bool equals(const MemRegion mr2) const { // first disjunct since we do not have a canonical empty set return ((is_empty() && mr2.is_empty()) || (start() == mr2.start() && end() == mr2.end())); } size_t byte_size() const { return _word_size * sizeof(HeapWord); } size_t word_size() const { return _word_size; } bool is_empty() const { return word_size() == 0; } }; // For iteration over MemRegion's. class MemRegionClosure : public StackObj { public: virtual void do_MemRegion(MemRegion mr) = 0; }; // A ResourceObj version of MemRegionClosure class MemRegionClosureRO: public MemRegionClosure { public: void* operator new(size_t size, ResourceObj::allocation_type type) { return ResourceObj::operator new(size, type); } void* operator new(size_t size, Arena *arena) { return ResourceObj::operator new(size, arena); } void* operator new(size_t size) { return ResourceObj::operator new(size); } void operator delete(void* p) {} // nothing to do }; #endif // SHARE_VM_MEMORY_MEMREGION_HPP